I'm in the process of installing one on my niner, I'm using an OEM cooler that I harvested from a junked 95 zj, It tucks away perfectly in the factory location in front of the ac condenser, it mounts to the support braces of the inner grill. Anywhere in the airflow and somewhat protected from road debri would work.

I mounted mine right to the AC coil. I also got rid of the check valve while I was in there. I routed the lines so that the trans cooler would stay full after you shut it off. It has worked great and I cant even tell the difference.

I went with the Hayden 678. Do yourself a favor and get 2 compression fittings with hose barbs. A good parts store will be able to hook you up for less then 10$

I have the 679. I don't think anything bigger would fit without cutting. I didn't notice any lack of cooling from the AC when I put it on back in Vegas. I don't have it bolted to the A pillar so it's not touching the condenser.

So I'm trying to get my duck inline to replace my trans and I'm definitely going to put an aux trans cooler in. But how big of one should I get? It does get cold here in the winter but I don't want to have to worry about the trans overheating again.

Also I should probably change filter/ fluid and Adjust the bands. I was told the trans are good if you adjust the bands every 20k miles. Any input would be greatly appreciated.